Liao W, Li S, Lu C, Peng M.

 BMC Genet. 2018 Jul 13;19(1):45. doi: 10.1186/s12863-018-0627-6.

 Abstract

BACKGROUND:

Glutathione S-transferases (GSTs) have been reported to regulate the plant tolerance to environmental stresses. Many plant GSTs exhibited the roles on promoting tolerance to drought stress, oxidative stress and plant hormones. The biological function of GSTs has been well characterized in Arabidopsis thaliana in response to exogenous environmental stresses. However, their regulation function under exogenous environmental stresses regulating leaf abscission in cassava (Manihot esculenta Crantz) remained unknown.

RESULTS:

Here, 83 GSTs were identified from tropical plant cassava. The amino acid motifs and phylogenetic analyses indicated that MeGSTs were divided into 9 classes. The global expression analyses were carried out to analyze the gene expression patterns of MeGST in cassava abscission zones by comparing the MeGST genes expression patterns in both ethylene and drought induced cassava leaf abscission. Totally, 34 GSTs were detected to express in both ethylene and drought induced leaf abscission in cassava abscission zones. Comparison of GST expression profiling between ethylene and drought induced leaf abscission suggested that Tau GST genes showed with the similar expression in both treatments induced leaf abscission in cassava abscission zone. GO annotation indicated that all 17 Tau GST genes participated in the pathway of toxin catabolism (GO: 0009407). The expression levels of 17 Tau MeGST genes were analyzed in two cassava cultivars, 'SC124' and 'Arg7', the two cultivars exhibit different levels of leaf abscission when suffered from the same environmental stress. Higher expression levels of Tau MeGSTs were detected in the precocious abscission Arg7 cultivar, while lower expression levels in delayed abscission SC124 cultivar. All the results indicated that Tau MeGSTs have the function in regulation the cassava leaf abscission under environmental stresses.

CONCLUSION:

Analysis of the expression patterns of GSTs in various abscission-promoting treatments in cassava abscission zones helps us to understand the possible roles of GSTs in cassava leaf abscission.

See: https://www.ncbi.nlm.nih.gov/pubmed/30005656

 Figure 1: Phylogenetic tree construction of all GSTs from cassava and Populus. 83 cassava GSTs and 81 Populus GSTs were analyzed using ClustalW, and the phylogenetic tree was constructed by MEGA 5.0 software using the neighbour-joining method (based on the p-distance model with 1000 bootstrap replicates). Each group is represented by a specific colour.